Printer

Abstract

It is intended to provide a printer which can prevent dust from entering and adhering to a printing medium, thereby avoiding entry of the dust to or near a print head, and can improve print quality. A first cover covers a first paper projection port through which paper as the printing medium is projected when the paper is inside a housing. This can prevent the entry of the dust through the first paper projection port to the housing. Furthermore, the first cover swings about a first engagement portion by pressure of a front end of the paper to cover the paper when the paper is projected through the first paper projection port in the forward feeding motion by the feeding device such as a paper feeding roller.

1. A printer comprising:
 a printing device; 
 a printing medium to be printed by the printing device; 
 a feeding device that feeds the printing medium forward and backward; 
 a housing that covers the printing device and the feeding device and that is provided with a first engagement portion and a third engagement portion; 
 a first paper projection port provided in the housing, through which the printing medium is temporarily projected outside the housing; 
 a first cover arranged to swing about the first engagement portion by pressure of a front end of the printing medium when projected through the first paper projection port in the forward feeding motion by the feeding device to cover the projected printing medium; 
 a second paper projection port provided in the housing, through which the printing medium is temporarily projected outside the housing; and 
 a second cover arranged to swing about the third engagement portion by the pressure of the rear end of the printing medium when projected through the second paper projection port in the backward feeding motion by the feeding device to cover the projected printing medium; 
 wherein a chamfered depression is provided in a free end of the second cover to support the rear end of the printing medium when the second cover swings about the third engagement portion by the pressure of the printing medium to cover the printing medium. 
 
     
     
       2. The printer according to  claim 1 , wherein the second cover is adapted to be returned by its own weight to a position to close the second paper projection port in the forward feeding motion of the printing medium by the feeding device. 
     
     
       3. The printer according to  claim 1 , wherein the first cover is provided with a side cover along a side thereof. 
     
     
       4. The printer according to  claim 1 , wherein a chamfered projection is provided in the free end of the second cover to support the rear end of the printing medium when the second cover swings about the third engagement portion by the pressure of the printing medium to cover the printing medium. 
     
     
       5. The printer according to  claim 1 , further comprising:
 a detection device that detects the rear end of the printing medium, 
 wherein the feeding device includes a pair of rollers that feeds the printing medium forward and backward, and 
 based on a detection signal from the detection device that detects the rear end of the printing medium in the backward feeding motion, the rollers tightly hold a predetermined portion of a front end of the printing medium to stop feeding motion of the printing medium before the rear end of the printing medium is projected through the second projection port. 
 
     
     
       6. The printer according to  claim 5 , further comprising:
 a tray that stores therein the printing medium so that the printing medium is to be drawn out of the tray in the forward feeding motion by the pair of rollers that feed the printing medium forward and backward: and, 
 a return preventing-feeding member that prevents the printing medium from returning to the tray in the backward feeding motion. 
 
     
     
       7. The printer according to  claim 1 , wherein the printing medium is made of a base material that is 0.18 mm or more in thickness. 
     
     
       8. The printer according to  claim 1 , wherein the first cover is adapted to be returned by its own weight to a position to close the first paper projection port in the backward feeding motion of the printing medium by the feeding device. 
     
     
       9. The printer according to  claim 1 , wherein the first cover includes a second engagement portion in a free end thereof to hold the front end of the printing medium when the first cover swings about the first engagement portion by the pressure of the printing medium to cover the printing medium. 
     
     
       10. The printer according to  claim 1 , further comprising:
 a detection device that detects the front end of the printing medium, 
 wherein the feeding device includes a pair of rollers that feeds the printing medium forward and backward, and 
 based on a detection signal from the detection device that detects the front end of the printing medium in the forward feeding motion, the rollers tightly hold a predetermined portion of a rear end of the printing medium to stop feeding motion of the printing medium before the front end of the printing medium is projected through the first projection port.